The dose delivered to a patient from proton therapy remains uncertain, in particular the positioning of the distal edge and lateral displacement of the proton or charged particle beam, and the dose delivered. Current treatment quality assurance methods to monitor these parameters include positron emission tomography (PET) and the detection of prompt gammas (PGs). PET is based on the detection of the production of gammas from the positron annihilation after positron decay due to proton induced nuclear reactions with endogenous molecular in human tissue, specifically oxygen, nitrogen and carbon. The detection of PGs, the emitted gamma accompanying the decay of excited nuclei from proton interactions within tissue. However, some weaknesses in these methods include sensitivity, modest spatial resolution, post-treatment assessment (for PET method), and non-linearity and accuracy of the method relative to dose deposited.
Accordingly, it remains desirable to provide a clinically viable diagnostic method of 3D dosimetric imaging and treatment beam delivery in vivo during the time of treatment (beam delivery).